# Source: https://trigger.dev/docs/guides/example-projects/realtime-csv-importer.md

> ## Documentation Index
> Fetch the complete documentation index at: https://trigger.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Next.js Realtime CSV Importer

> This example Next.js project demonstrates how to use Trigger.dev Realtime to build a CSV Uploader with progress updates streamed to the frontend.

## Overview

The frontend is a Next.js app that allows users to upload a CSV file, which is then processed in the background using Trigger.dev tasks. The progress of the task is streamed back to the frontend in real-time using Trigger.dev Realtime.

* A [Next.js](https://nextjs.org/) app with [Trigger.dev](https://trigger.dev/) for the background tasks.
* [UploadThing](https://uploadthing.com/) to handle CSV file uploads
* Trigger.dev [Realtime](https://trigger.dev/launchweek/0/realtime) to stream updates to the frontend.

## GitHub repo

<Card title="View the Realtime CSV Importer repo" icon="GitHub" href="https://github.com/triggerdotdev/examples/blob/main/realtime-csv-importer/README.md">
  Click here to view the full code for this project in our examples repository on GitHub. You can
  fork it and use it as a starting point for your own project.
</Card>

## Video

<video controls className="w-full aspect-video" src="https://github.com/user-attachments/assets/25160343-6663-452c-8a27-819c3fd7b8df" />

## Relevant code

* View the Trigger.dev task code in the [src/trigger/csv.ts](https://github.com/triggerdotdev/examples/blob/main/realtime-csv-importer/src/trigger/csv.ts) file.
* The parent task `csvValidator` downloads the CSV file, parses it, and then splits the rows into multiple batches. It then does a `batch.triggerAndWait` to distribute the work the `handleCSVRow` task.
* The `handleCSVRow` task "simulates" checking the row for a valid email address and then updates the progress of the parent task using `metadata.parent`. See the [Trigger.dev docs](/runs/metadata#parent-and-root-updates) for more information on how to use the `metadata.parent` object.
* The `useRealtimeCSVValidator` hook in the [src/hooks/useRealtimeCSVValidator.ts](https://github.com/triggerdotdev/examples/blob/main/realtime-csv-importer/src/hooks/useRealtimeCSVValidator.ts) file handles the call to `useRealtimeRun` to get the progress of the parent task.
* The `CSVProcessor` component in the [src/components/CSVProcessor.tsx](https://github.com/triggerdotdev/examples/blob/main/realtime-csv-importer/src/components/CSVProcessor.tsx) file handles the file upload and displays the progress bar, and uses the `useRealtimeCSVValidator` hook to get the progress updates.

## Learn more about Trigger.dev Realtime

To learn more, take a look at the following resources:

* [Trigger.dev Realtime](/realtime) - learn more about how to subscribe to runs and get real-time updates
* [Realtime streaming](/realtime/react-hooks/streams) - learn more about streaming data from your tasks
* [Batch Triggering](/triggering#tasks-batchtrigger) - learn more about how to trigger tasks in batches
* [React hooks](/realtime/react-hooks) - learn more about using React hooks to interact with the Trigger.dev API